ELI5 : What does it make it difficult to fake a vintage trading card like the 1st edition charizard or the alpha black lotus? Why was only wizards of the coast able to create these cards? Why haven't fakes been authenticated as genuine yet?

ELI5 : What does it make it difficult to fake a vintage trading card like the 1st edition charizard or the alpha black lotus? Why was only wizards of the coast able to create these cards? Why haven't fakes been authenticated as genuine yet?